The present invention relates to a very wide band primary source for a space communications antenna and more exactly for the antenna of a ground-based station operating with frequency re-utilization, that is to say utilization of the same frequency band in two orthogonal polarizations.
Space communications use at the present time two groups of frequency bands. In the first group, the up-going connection, called "emission" hereafter, takes place between 5.925 and 6.425 GHz and the down-coming connection, called "reception" hereafter, takes place between 3.7 and 4.2 GHz. In the second group, the up-going connection, or "emission", takes place between 14 and 14.5 GHz and the downcoming connection or "reception" between 10.95 and 11.7 GHz.
Recently, widening the frequency bands has been contemplated so as to increase the transmission capacity; now, these new bands are considerably wider since the band for emission goes from 5.85 to 7.075 GHz and the band for "reception" from 3.4 to 4.2 GHz and from 4.5 to 4.8 GHz.
Known primary sources, two examples of which will be given further on, do not allow these bands to pass, all the more so since the desired performances are greater than or at least equal to those obtained with the existing primary sources with frequency re-utilization.
The object of the present invention is to provide a primary source requiring a mode extractor means and capable of operating in the new frequency bands mentioned above.